40MM identification

I am looking for an identification on a 40mm projectile. I believe it is a newer type of projectile for shoulder fired grenade launchers such as the M203 and M79.

The projectile is not available for examination, but from photos and description I have the following data.

It is a 40mm and appears to be green plastic, with a flat point with a slight taper on the outside and a hollow that starts with a broad taper before becoming parellel sided. Parellel section about 13 mm diameter.

It has the following markings.

40 mm x 45
??? : 18 PIA

Maybe somekind target marker?

hello with the writing :
first I’m surprise because low velocity grenade are 40 x 46
why writting 40 x 45 ?
IMPACT SIGN are generally the term for grenade who are using for training they have color powder for mark the impact in the target
NIC for the german compagny NICO and 08/05 for the date of production august 2005

If you have pictures I can tell more I saw some grenade of this compagny.

Will try for a picture but could take a few days. I don’t have the item or the pictures, and this is a busy time of the year, for everyone else as well as me no doubt.
Thanks for the info so far.