The one shown above is for a Yanmar KM35A transmission and is a direct replacement for Yanmar part 177070-62450.  

These hard annodized aluminum versions for sale both as a complete assembly or just the vented cap (YM1001-00) that can be used with any existing Yanmar transmission dipstick that has the same type of hollow dipstick tube. So you can purchase just the Cap only (YM1001-00) and take the hollow tube out of the original Yanmar plastic cap (just push the tube up into the cap and a plastic insert will pop out of the Yanmar cap to allow the tube to be removed) and put it into my aluminum cap and no more plastic cap problems.

Part number	Description	Price
YM1001-00	Dipstick Cap only to replace the plastic cap Can be used with original Yanmar dipstick tube	$75
YM1001-01	Aluminum dipstick cap/tube assembly (4.7"). Replaces Yanmar 177073-02450 & 177070-62450. For use on KM35A/A2, KM4A2 & Beta Marine TTMC35A	$85
YM1001-02	Aluminum dipstick cap/tube assembly (3.7"). Replaces Yanmar 177088-02451. For use on KM2A/C/P/P1, KM3P, KM3V, GM series. NOT for KM2A/C, KM3-A or JH series that have metal 16mm plug dipstick	$85
YM1001-03	Aluminum dipstick cap/tube assembly (7.07"). Replaces Yanmar 177074-02500. For use on KM5A	$85
YM1001-04	Aluminum dipstick cap/tube assembly (2.95"). Replaces Yanmar 177070-02450. For use on KM35P/P1	$85
YM1001-05	Aluminum dipstick cap/tube assembly (5.45"). Replaces Yanmar 177074-02450. For use on KM3A/A1, KM4A/A1	$85