Casio Edifice EFS-S660 Solar Chronographs Go on Sale in Japan With Sapphire Crystal and 100-Meter Water Resistance
Casio has officially released two new Edifice solar chronograph watches in Japan, and they bring a surprisingly strong feature set for the price. The Casio Edifice EFS-S660D-1AJF and EFS-S660PB-1AJF are now available through Casio Japan for ¥33,000, which is roughly $208.
What makes the new Casio Edifice EFS-S660 series especially appealing is the combination of sapphire crystal, solar charging, and 10-bar water resistance at this price point. Many solar chronographs in a similar range still rely on mineral glass and offer lower water resistance, so Casio is clearly aiming to give buyers a more durable everyday sports watch without pushing the price too high.
The EFS-S660D-1AJF is the more traditional stainless steel version. It features a polished steel case, an integrated stainless steel bracelet, and a one-touch three-fold clasp. A blue chronograph seconds hand adds a sporty accent to the dial, while the full metal build gives the watch a more substantial feel on the wrist. This model weighs 129 grams.
The EFS-S660PB-1AJF takes a different approach with a lighter, more motorsport-inspired design. It uses a black resin strap, bringing the total weight down to just 71 grams. The case has a gray ion-plated finish, paired with a black ion-plated bezel and red chronograph hands. This version also includes Toyota Racing branding, tied to Casio’s partnership in the FIA World Endurance Championship. Notably, this is the first time such branding has appeared on an entry-level Edifice model.
Both watches share the same core specifications. The case measures 45.3 x 38.3 x 11.6 mm, with a width kept under 39 mm. That narrower case profile should make the EFS-S660 series easier to wear than the dimensions might initially suggest, especially for those who prefer a sport chronograph that does not feel oversized.
Casio has fitted both models with sapphire crystal featuring an internal anti-reflective coating. This should improve scratch resistance while helping visibility under bright light. The watches are also rated for 10-bar water resistance, making them suitable for daily use, rain, hand washing, and swimming.
The chronograph function can measure elapsed time down to 1/20 of a second for up to 60 minutes and supports split-time measurement. A tachymeter scale around the dial allows users to calculate average speed, reinforcing the racing-inspired identity of the Edifice lineup.
Another interesting detail is the dial design. Because these watches are solar-powered, the dial needs to allow enough light to pass through to the solar cell underneath. Casio used a textured dial finish to create visual depth without blocking too much light, balancing style with practical solar performance.
At the moment, Casio has not confirmed whether the EFS-S660D-1AJF or EFS-S660PB-1AJF will be released internationally. Both models are currently available in Japan, while some Japanese retailers may still show them as preorders depending on their own stock schedules.
For buyers looking for an affordable Casio Edifice solar chronograph with sapphire crystal, strong water resistance, and motorsport styling, the new EFS-S660 series looks like one of the more compelling releases in the lineup.
