Just acquired a nice DT1 cylinder with a matching Wiseco piston/rings/pin/bearing setup. No circlips.  Is the Wiseco CW18 circlip correct for this piston?  .This piston uses the L-type top ring.  Package deal also included another DT1 cylinder(wrist pin damage), two standard and one TK cylinder heads. Last of someone's old DT1 stuff.  Thanks
 

Many earlier Wiseco had "square" profile grooves machined and designed for "Spirolox" clips.  Would be worth calling Wiseco to see if they can ID what you need.

Mark,
I remember vaguely the Spirlox type clips. I'll examine the circlip groves with a magnifier for round or square profile.
I've contacted Wiseco before, fairly helpful. Thanks

Checked the groove, square edge-CS18 spirolox circlips. Contacted Wiseco, they confirmed. No longer offered by Wiseco but found a set on ebay-not cheap! At least can use the piston kit. Interested to learn more about the circled "TK" casting on the heads and cylinders. Does the TK mean anything? The one head has it, 2 plug hole-tip and rear. Smaller combustion chamber than stock heads. One of the cylinders has TK, oposite the 246cc. Stock cylinder head has a TK casting. Google AI say these parts are from the DT1MX models, similar to GYT parts. Don't have info on port size/height. Thanks